This invention relates to shot blasting machines for treatment of cast parts and, in particular, the removal of the sand molds. It has been generally accepted in the casting industry that the removal of sand both externally and internally from a casting is best achieved by vibratory equipment wherein the casting is shaken and jolted to loosen the sand and free the casting from the mold. Blast cleaning equipment has also been developed which performs a similar function by utilization of high velocity impacts of particulate such as steel shot, grit and the like. Both the vibratory and blast cleaning equipment have the drawback that they cannot remove sand from intricate passages or cores in the castings, particularly where these passages have very small access holes through which the sand must be removed.
In such instances, the general practice is to rap the casting with a hammer manually and then turn the casting to permit the loosened sand to drain out. It is an object of the present invention to overcome the necessity for such manual labor in the removal and cleaning of castings.
Accordingly, it is an object of the present invention to provide a machine which subjects the cast part to vibratory and blasting action whereby an improved result is obtained from the combined action of vibratory and impact treatment of the part for sand removal.
It is another object of the present invention to provide a vibratory blasting device in conjunction with shot blasting whereby the cast part which is treated automatically turned in a manner so as to permit removal of sand through small access passages in the casting.
Other objects and advantages of the invention will become apparent from the remaining portion of the specification.